Liquid Crystal Display Signal Processing for Response Speed
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Solution Overview
Problem
The slow response speed of liquid crystal molecules in liquid crystal displays leads to display quality deterioration, particularly in achieving desired luminance, as the time required for the pixel voltage to reach a target voltage is prolonged, especially when the difference between the target and previous voltages is significant.
Innovation Solution
A method involving dynamic capacitance compensation (DCC) and temporal gamma mixing (TGM) is employed, where the current image signal is processed to generate a correction image signal by doubling frames and applying different gamma curves, with a flag signal used to adjust the weight value for post-processing, thereby improving transmittance and lateral visibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If only the target voltage is applied from the start to achieve desired luminance, then the luminance can be reached quickly, but the pixel voltage may not reach the target voltage while the switching element is turned on due to slow liquid crystal response speed
Solution Approach 1:
The patent applies preliminary action by performing frame doubling and gamma curve correction on the current image signal before it is displayed. The correction image signal is generated in advance using the previous image signal and current image signal, preparing the liquid crystal molecules for the upcoming voltage change to ensure they can reach the target luminance within the available time.
Solution Approach 2:
The patent implements dynamics by dynamically adjusting the voltage application strategy based on the liquid crystal's response characteristics. The system uses dynamic capacitance compensation (DCC) and temporal gamma mixing (TGM) to adaptively modify the image signal, allowing the voltage to be applied in a manner that accounts for the slow response speed while maintaining luminance accuracy.
2Productivity
If the difference between target voltage and previous voltage is large, then the voltage change is more significant, but the liquid crystal response time is insufficient to reach the target voltage
Solution Approach 1:
The system performs preliminary processing by generating a correction image signal that anticipates the voltage change requirements. Using frame doubling and gamma curve selection, the system prepares the signal in advance so that when large voltage changes are needed, the liquid crystal molecules are already positioned to respond more effectively, reducing the time loss.
Solution Approach 2:
The patent changes parameters by applying different gamma curves (first gamma curve or second gamma curve) based on the luminance change conditions. When the luminance needs to increase rapidly, the first gamma curve is applied; when it needs to decrease, the second gamma curve is applied. This parameter change optimizes the voltage transition for different scenarios.
3Manufacturing precision
If frame doubling and gamma curve correction are applied to improve response speed, then luminance consistency is improved, but the processing complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the image signal processing into distinct stages: frame doubling, gamma curve selection, and correction image signal generation. Each stage handles a specific aspect of the signal processing, making the overall complex process more manageable and implementable through modular circuit design.
Solution Approach 2:
The correction image signal acts as an intermediary between the original image signal and the final displayed signal. This intermediary signal incorporates the effects of frame doubling and gamma curve correction, serving as a bridge that translates the complex processing requirements into a form that can be efficiently applied to the liquid crystal display.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances display quality by compensating for the slow liquid crystal response speed, ensuring faster voltage stabilization and improved luminance consistency, thereby preventing quality degradation and increasing transmittance and lateral visibility.
Implementation Method 1
a liquid crystal layer disposed therebetween and having dielectric anisotropy
Implementation Method 2
A voltage applied to the pixel electrodes and the opposing electrodes generates an electric field in the liquid crystal layer
Data Source
Figure 1
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AI summary
A image signal processing method of a liquid crystal display according to an exemplary embodiment of the present invention includes: receiving a previous image signal and a current image signal as two sequential input image signals; performing a first correction (DCC) and a doubling for the current image signal to generate a correction image signal comprising a plurality of doubled frames for the current image signal; and post-processing the portion of the plurality of doubled frames to generate a final correction image signal.